Protective device for autogenous apparatus



June 10, 1924. 1,497,197

H. w. c. scHR6DER PROTECTIVE DEVICE FOR AUTOGENOUS APPARATUS Filed Aug.18, 1921 HTTO/P/VEKF Patented June 10, 1924.

UNETED fiTATES snares rArENT curios.-

ANDEB IBERNEABD naliena, or FINKENBERG, LUBncx, enema.

rno'rncrrva nnvrcn non ao'roennocs nrrnm'rus.

Application filed August 18, 1921. Serial No. 4:93AM.

To all whom it may concem Be it known that I, HANs WILHELM Gums- TIANSonniinnn, a German citizen, residing at Lubeck, Germany, have inventedcertain a new and useful Improvements in Protective Devices forAutogenous Apparatus for which I have filed an application in ermany May2, 1918, which resulted in useful Design Patent No. 7 20,304, registeredOctome her 18, 1919), of which the following isa A specification.

In using autogenous apparatus for welding and cuttin metals which areworked by diflerent kin s of gases, e. oxygen and is another combustiblegas, exp osions of the steel cylinders or steel containers, and of thefittings attached thereto frequently occur. The cause of such explosionscan onl be ascribed to the fact that owing to the o okm ing. up of themouthpiece of the autogenous burner, one of the gases passes over intothe suppl pipe for the other gas and conse quent y there is formed inthis supply pipe under some circumstances as far as the steel aacylinder, a dangerous mixture of the gases. Or such dangerous mixturemay be already present in the steel cylinder owing to the latter havingbeen wrongly filled with the result that the mixture is passed out intothe supply pipeleadingto theburner. If under such circumstances theflame of the burner strikes back, the mixed gas present in the supplypipe will become ignited with the result that in most cases an explosionin the piping 36- or in the steel cylinder follows.

The object of the present invention therefore is to provide a protectivedevice or.

cartridge by means of which all the disadvantages above mentioned areavoided. This 40 is attained by interposing in the gas pipe a non-returnvalve and between the latter and the burner, in addition to thenon-return valve, an explosion resistance in the. form of a plate ordisc ofa fireproof m'a-a as terial such as sandstone, earthenware, fireclay, magnesium oxide, or the like, which, when the flame burns inwards,does not fuse or sinter, and so stops the explosion wave. And with thisend in view my invention consists in certain novel features ofconstruction and combinations of arts as will be hereinafter describedand pointed out in the claims with reference to the accompanying sheetof drawings in which is shown an example of the invention.

Figure 1 shows in elevation an oxy-hydrogen weldmg apparatus fitted upaccord- 111%!20 the present invention and lgure 2 1s a longitudinalsection, on a larger scale, of a protective cartridge constructedaccording to this invention and inserted 1n each of the two gas supplypipes.

Like reference letters indicate like parts.

As shown in-Figure 1 the welding apparatus consists of an oxygencylinder 0. and a hydrogen cylinder a each being provided with apressure reducin valve 6 and I) respectively, a protective ilevice c andc and a flexible pipe d and (1 both of which lead to a welding burner e.In this latter there takes place, in a special mixing chamber in frontof the outlet opening of the mouthpiece, a m1xture of oxygen and theother combustlble gas, which in this case is hydrogen. Now if while theapparatus is bemg used, the opening of the mouthpiece of the burnerbecomes wholly or artially choked up owing-to the entrance 0 dirt orllqllld metal, a mixture of the two gases may pass into one or other ofthe two su ply pipes d or d, the gas which is under tiEe lgher pressurepassing over into the supply pipe for the gas which is under the lowerpressure. According to the magnitude of the diiference between thepressures this mixed gas will flow back into the pressure reducing valveappertainin to the said suppIly pipe and even on into t e steelcylinder. nder such conditions, if the flame should strike back intheburner, the mixed gas in the supply pipe will be exploded, and if any ofsaid mixed gas is present in the ressure reducing valve and the steel 0lin er, the contents of the latter also, will caused to ex lode.

n order to keep any mixed gas which p ay have been formed,'away from thecorresponding pressure reducing valve and steel cylinder, and tointercept and render harmless expolsion waves of this mixed gasresulting from the striking back of the flame-from the burner, there islocated in each gas supply pipe, a protective apparatus or cartridge 0and c, the cartridge, in each instance, 1s preferably positioned betweenthe supply pipe d or d and the pressure reducing valve 5 or brespectivel, and is therefore always located upon t e low pressure sideof the reducmg valve. As the structural form or both the cartridges 0and o is the same, the illustration and description of only one of thesame e. g., the cartridge 0 will sufice for the comprehension of theinvention. This device consists of a cup-shaped cartridge case 0 see Figure 2, provided Witha non-return valve f, acted upon by a spring 7,and a connecting screw thread 9 n the gas inlet nozzle k, a sleeve c'containing a ,orous fireproof protective disc k of magri sium oxldeinserted gas-tight therein, and a cartridge cover m with a connectingscrew thread a on the cup shaped gas outlet nozzle 0. By screwing theparts 0 and m to ether the protective disc 2', la, is clamped rmly andthe joint-made gas-tight by the interposltion of annular packing discsor washers Z, so that all the gas which passes through the pi e and theprotective cartridge is compe ed to pass through the protective disc orplate is, which as regards its porosity, is of such a nature thatitallows gas to pass'through it in both directions. The gas when flowingin the right dlrection opens the non-return valve f and then flowsthrough the protective plate I: to the burner. Any gaseous mixturepassin back in the reverse direction through t e protective plate ishowever immediately stopped by the non-return valve f whichautomatically closes and cuts 03 the mixture so that it cannot get intothe pressure reducing valve and the steel cylinder. Furthermore theprotective plate It stops any explosion wave coming from the burner onits front surface, so that the non-return valve is not touched by theexplosion wave and if any mixed gas should be contained in the pressurereducing valve and the steel cylinder this gas cannot be ignited. Theflame on the contrary goes on burning at the front face of theprotective late until the mixed gas present has burned out or'unti'l thestop valve or the pressure reducing valve is closed.

Without the non-return valve f the rotective plate is would, as can beseen, a 0rd no per tion of the gas mixture into the pressure reducingvalve and the steel cylinder, and on the subsequent use of this cylinderfor other purposes an accident might easily happen. The combinedprovision of a nonreturn valve and of a protective plate which stops theexplosion wave and is composed of porous, fireproof material, such forexample as ma esium oxide, sandstone, or the like, o era the greatestprotection ect safeguard against the penetra t eater against thedangerous effects ot the bachward how of the gas, formation of mixed gasand striking back of the flame.

The manufacture of the protective discs or plates may be convenientlycarried out by mouldin the plates from a mixture of granulated hreproofmaterial such as sandstone, magnesium oxide, fire clay, etc. andgranulated combustible material, e. g. coal dust, or the like, and thenafterwards burning them. By so treating the plates thus prepared thecombustible terial burns awa and thus the necessary porosity is providedwhich latter can be related by the porportion selected for the mixtures.

The increased resistance which is natural- 1 produced by the non-returnvalve and the porous protective plate, but which is in itself verysmall, can be easily overcome by a moderate increase in the pressure offthe oxygen and also of the hydrogen. Protective plates which becomedefective can be easily replaced by spare plates.

It is preferable to provide such a protective cartridge for eac of thetwo as pipes d and al but in any case one s ould be provided for thepipe which supplies the gas at the lower working pressure. Instead ofbeing placed on the ressure reducing valve the protective cartri ge maybe placed on the burner. It may also be made in two parts and the partwhich contains the protective plate mounted on the burner and the CIDpart which contains the non-return valve on the pressure reducing valve.

I claim:

1. A protective device of the hind d scribed comprising an inlet nozzle,a cupshaped case at the outlet end thereof and comprising an integralpart of said nozzle, a non-return valve in said inlet nozzle between itsends, an outlet nozzle detachably connected with said case, and aflame-arresting discclamped in said case by said outlet nozzle andobstructing the axial passage through said device. I

2. A protective device of the hind described comprising andnlet nozzle,a cup shaped case at the outlet end thereof and comprising an integralpart of said nozzle, a non-return valve in said inlet nozzle between itsends an outlet nozzle detachably connected with said case, a sleeveclamped in said case by said cup-shaped outlet 111041- zle, and a porousdisc of fire-proof material fixed in said sleeve and obstructing theaxial passage through said device.

HANS WlLllllElLl (ClllllSTllAll @Cllilfltlllllill, Witnesses:

Fnmx Jonrrocronrn, lEm/mn A. H. L. Mmtrmmorn Tilt)

